614 nEPORT— 18C3. 



attpn<l« thoir idpntifiontion. Dt. Cooper found verylarjreTalvps fresenihlinfr 

 tkhizi)th/'r>!fi) in almndance, but much detoniied by the entrance of .sand, and 

 appan'ntly killed bv the fresh waters of the jn'eat Hood. The larjre shells 

 btlon^j: to two ver\- di.stinct species, which are probably those of Conrad ; 

 anionjr the small sliel's i? perhaps a thii-d, which may be Dr. Gould's sup- 

 pressed nfimita. 



1;J(5. lidffa uiidiiliita. This rei .arkable reyeree of the Atlantic R. cannliailcda ia 

 also contirnied by rare valves from the S. Diegan di:<trict. It is not con- 

 peneric with Harvella eleyans, to which it bears but a slight external resem- 

 blance. 



1;>7. 2a})e>i tnicrn'mn. Large dead valves of this very distinct species were found 

 with the StandelUe, and coufiiin Col. Jewett's young shells described as from 

 Panama. 



1-M*. Pecteii fxtucicostattis. Sta. Barbara Is. [Described from Col. Jewett's valves.] 



l.}!>. iJii/lu Qiioi/ii. 8. Diego. Maz. Cat. no. 220. 



1-M). Triincatella Ctdifoniica. S. Diego. 



141. Acinrra rosacea. Monterey to 8. Diego. This shell is named /)j7fo/»M, Midd., 



in Mus. Cuming, but does not agree with the diagnosis. It can hardly be 

 distinguished from Her'm specimens of A. viryinea. It was first brought by 

 Col. Jewett, but refeiTed to Panama. 



142. Amphithalamus inclmm. S. Diego. [Several specimens of ths minute but 



remarkable new genus confirm a solitary shell in Col. Jewett's mixed 

 collections.] 



143. Uli/nre/Ui mmphx. Verv variable in sculpture, as befits the species which 



forms the northern limit of a group common between the tropics. Col. 

 Jewett's shell was in poor condition, and supposed to be the young of s 

 fnilf species. 



1 44. Volrarina varia. S. Diego, Cat. Is. [Sta. Barbara, Jeirett ; also C. S. I.ucas."] 



145. NaxMi CoiqHii, Fbs. S. Diego, Cat. Is. [This Kollettian shell has a double 



right to its name, now that Dr. Cooper has ascertained its habitat.] 



The information on station, &c., which Dr. Cooper lias sent with regard to 

 ])reviously known species, will be found incorporated in the general taV)lf of 

 the fauna. The following notes, extracted from his letters, are too valuable 

 to be omitted : — 



Ilaliotis Caltfornt'ensis. " This form is so rare that I think it only a var. of 

 Crac/ierodii." 



Ilaliofis. Several specimens from the Farallones present characters inter- 

 mediate between corni(/ata, rufescens, and Kamtuchatkana. It is not yet 

 ascertained whether they a»e hybrids or a distinct species. 



" Livona picoides I have not found, though I have seen fresh ones from Pt. 

 Conception." 



* ? Serpulorhii sqtiamii/enis. Common south of Pt. Conception ; has no 

 operculum." \The young begins like V. aueliiim, Miirch.] 



Macron lividus. I'oint Loma, S. Pedro, common ; extends northwards f. tht 

 Farallones. [ = Planazi» niffritcUa, Newcomb, MS.; non auct.] 



" OUvvlla semistriata, Gray, fide Newc, is a species found N. of Monterey onlv." 

 [.\s Dr. Gray's species is from Panama, that of Newcomb is probably 

 O bo'tica.] 



** Kassa mterstriata, Conr., foss. (?= N. paupera, Gld.) ; resembles N. fossata, 

 Gld { = Ii. elegans, Rve.*), but distinct. Common south from Sta. Barbara." 

 [Probably =N. perpinguis, lids. N. paupera is quite distinct, =iV. striaia, 

 C. B. Ad., teste Cuming.] 



** Fmin-elln violacea I have seen from Catalina Is." [Rsch.'s shell is generally 

 considered vS. American. ? May Dr. Cooper s be a form of volcano.^ 



Acnu(<e. With regard to limpets and other variable shells, Dr. C. writes t— 

 " From my examination of large nuinl)ei3 of specimens, I am more and 

 more compelled to believe that hybrids are very frequent between allied 



• Sassa elejaiu was first published, bv J, Sowerbj', in the Min. Conch. 1821. 



100 



